[SOLVED]820-2850-a no green light on charger no powering up.

[speedyaction]

Strange situation here. 820-2850-a no powering up no green light on charger.
checked voltage:
PPBUS_G3H: 12.64v
PPBUS_CPU_IMVP_ISNS: 12.63v
PPDCIN_G3H: 18.99v
PP3V42_G3H: 3.41v

PP5V_S5: 4.99v
PP5V_S3: 0.00v

 

[dukefawks]

ACOK? Known good magsafe board? Voltage on ADAPTER_SENSE?

 

[speedyaction]

ADAPTER_SENSE : 18.80v
SMC_BC_ACOK :3.2v
SMC_BC_ACOK_VCC :0.00v
checkedf with another magsafe board and is this same

 

[aprendiz]

ADAPTER_SENSE 18.80V??? Really?? I'm pretty sure you are measuring the wrong pin...

 

[aprendiz]

Also with SMC_BC_ACOK at 3.2v SMC_BC_ACOK_VCC should be 3.42V, is 3.42V present at U6901 pin 5??? If yes, then should be a bad U6901 and/or corroded trace...

 

[speedyaction]

i measure on testing point next to charger connector on main board. but when i measure on pin 5 on magsafe connector is 0.42v

 

[speedyaction]

u6901 pin 5 : 3.42v
u6901 pin 4 :3.40v
u6900 pin 4: 3.41v

 

[aprendiz]

ADAPTER_SENSE : 18.80v
SMC_BC_ACOK :3.2v
SMC_BC_ACOK_VCC :0.00v
checkedf with another magsafe board and is this same

If pin 4 from U6901 is 3.40V then SMC_BC_ACOK_VCC should be 3.40V too, maybe you have a broken trace...

 

[speedyaction]

SMC_BC_ACOK_VCC is 3.4v on u6901 pin 4

 

[dukefawks]

18V on ADAPTER_SENSE???? Double check please.

DO NOT USE COMMENTS, make a reply

 

[aprendiz]

Right now i cant trust on any of your measurements, please recheck all..

 

[speedyaction]

ok. i done jumper from pin 5 on magsafe connector to u6900 pin 5 and now motherboard is working thx for all guys . all of you give me little bit to think how is it work and now is powering up. Done!!!